Mr Gove, who is campaign for Brexit , said: “The facts are that the European Court of Justice is not bound by this agreement until treaties are changed and we don’t know when that will be.”

He added: “I do think it’s important that people also realise that the European Court of Justice stands above every nation state, and ultimately it will decide on the basis of the treaties and this deal is not yet in the treaties.”

But the Attorney General, Jeremy Wright QC MP, said the Justice Secretary was wrong.

In a tersely-worded statement, Wright said: “The suggestion that this agreement does not have legal effect until it is incorporated into EU treaties is not correct.

“It has legal effect from the point the UK says it intends to remain in the EU, and the European Court must take it into account.

"The job of the European Court is to interpret the agreements between the 28 nation states of the EU.

"This is one of those agreements, with equivalent legal force to other agreements such as treaties.

“That is not just my opinion – it is the opinion of this government’s lawyers, lawyers for the EU, and, I suspect, the majority of lawyers in this country.”

Downing Street also rejected Gove’s analysis, with spokesman saying: “It is not true that this deal is not legally binding. Britain’s new settlement in the EU has legal force and is an irreversible international law decision that requires the European Court of Justice to take it into account.”

Friendly fire: Pals Michael Gove and David Cameron have fallen out over the EU referendum (Image: Getty)